Electronic module, electronic equipment, imaging sensor module, imaging apparatus, and display apparatus

ABSTRACT

An electronic module has a flexible wiring member, a wiring circuit board, and a conductive connection member. The flexible wiring member has a flexible base, a first wiring layer formed on at least one face of the flexible base, and a first electrode formed of the first wiring layer at the end part that is not covered by a first insulating layer. The wiring circuit board has a base provided with a wiring, a second insulating layer having opening formed on at least one face of the base, and a second electrode formed in the opening. The conductive connection member connects the first electrode and the second electrode to each other. The end of the flexible wiring member is arranged above the opening in plan view.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an electronic module, an electronicequipment, an imaging sensor module, an imaging apparatus, and a displayapparatus.

Description of the Related Art

Japanese Patent Application Laid-Open No. 2005-101026 discloses atechnique relating to joining of a flexible circuit board to a circuitboard by soldering. In the technique disclosed in Japanese PatentApplication Laid-Open No. 2005-101026, when a group of electrode pads onthe circuit board and a group of solder terminals on the flexiblecircuit board are attached to each other and then thermo-compressionbonding is performed downward on the flexible circuit board via solder,a stopper structure including a rib part via a dam part is formed at theend portion of the flexible circuit board.

Japanese Patent Application Laid-Open No. 2005-101026 discloses that therib part comes into contact with the circuit board duringthermo-compression bonding, thereby the applied pressure is suppressed,and a gap for a solder pool can be formed between the group of electrodepads on the circuit board and the group of solder terminals on theflexible circuit board.

In the technique disclosed in Japanese Patent Application Laid-Open No.2005-101026, however, a region having the area corresponding to the dampart and the rib part of the flexible circuit board is required to besecured on the circuit board so that the rib part of the flexiblecircuit board can come into contact with the circuit board.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, provided is anelectronic module including: a flexible wiring member including aflexible base, a first wiring layer formed on at least one face of theflexible base, and a first electrode formed of the first wiring layer atan end part that is not covered by a first insulating layer; a wiringcircuit board including a base provided with a wiring, a secondinsulating layer having an opening formed on at least one face of thebase, and a second electrode formed in the opening; and a conductiveconnection member that connects the first electrode and the secondelectrode to each other, wherein an end of the flexible wiring member isarranged above the opening in plan view.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a sectional view illustrating the structure of a connectionportion between a flexible wiring member and a printed wiring board,which is a wiring base, in an electronic module according to a firstembodiment of the present invention.

FIG. 1B is a top view illustrating the structure of the connectionportion between the flexible wiring member and the printed wiring board,which is a wiring base, in the electronic module according to the firstembodiment of the present invention.

FIG. 2 is a sectional view illustrating the structure of a connectionportion between a flexible wiring member and a printed wiring board,which is a wiring base, in an electronic module according to a secondembodiment of the present invention.

FIG. 3A, FIG. 3B, and FIG. 3C are sectional views illustrating amanufacturing method of the electronic module according to the firstembodiment of the present invention.

FIG. 4A, FIG. 4B, and FIG. 4C are sectional views illustrating anothermanufacturing method of the electronic module according to the firstembodiment of the present invention.

FIG. 5 is a sectional view illustrating an electronic componentaccording to a third embodiment of the present invention.

FIG. 6A, FIG. 6B, and FIG. 6C are schematic diagrams illustrating animaging unit according to a fourth embodiment of the present invention.

FIG. 7A, FIG. 7B, and FIG. 7C are sectional views illustrating thestructure of connection portion between a flexible wiring member and aprinted wiring board, which is a wiring base, in the imaging unitaccording to the fourth embodiment of the present invention.

FIG. 8A, FIG. 8B, and FIG. 8C are sectional views illustrating anotherstructure of a connection portion between a flexible wiring member and aprinted wiring board, which is a wiring base, in the imaging unitaccording to the fourth embodiment of the present invention.

FIG. 9 is a diagram illustrating a general configuration of an imagingapparatus as an example of an electronic equipment according to a fifthembodiment of the present invention.

FIG. 10A and FIG. 10B are diagrams illustrating a general configurationof a display apparatus as an example of an electronic equipmentaccording to a sixth embodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS

Embodiments for implementing the present invention will be described indetail below with reference to the drawings. Note that the presentinvention is not limited to the embodiments described below and can bechanged as appropriate within the scope not departing from the spirit ofthe present invention. Further, in the drawings described below,components having the same function are labeled with the same referencesymbols, and the description thereof may be omitted or simplified.

Electronic Module

First Embodiment

The structure of the electronic module according to the first embodimentof the present invention will be described with reference to FIG. 1A andFIG. 1B.

FIG. 1A is a sectional view illustrating the structure of a connectionportion between a flexible wiring member and a printed wiring board,which is a wiring base, in an electronic module according to the presentembodiment.

As illustrated in FIG. 1A, an electronic module 100 according to thepresent embodiment has a flexible wiring member 4 and a printed wiringboard 9 that is a wiring base on which the flexible wiring member 4 isdirectly connected and mounted by soldering. The flexible wiring member4 is a film-like flexible printed wiring board with bendability. Unlikethe flexible wiring member 4, the printed wiring board 9 is a rigidprinted wiring board that is a rigid plate.

The flexible wiring member 4 has a flexible base 1, a flexible wiringlayer 2 that is a first wiring layer, and a coverlay 3 that is a firstinsulating layer. As described below, the flexible wiring member 4 hasone or more conductive layers as a flexible wiring layer 2, and isconfigured such that the conductive layers are stacked as an insulatinglayer via the flexible base 1. Note that, in the present embodiment,while a case where the wiring layer in the flexible wiring member 4 is asingle layer is described, the wiring layer is not limited to a singlelayer and may have two or more layers.

The flexible base 1 is a sheet-like or film-like insulating base formedof a resin or the like, for example, and has flexibility andbendability. Thus, the flexible wiring member 4 is configured to bedeformable, such as to be bent. The insulator forming the flexible base1 may have electrical insulation. As an insulator forming the flexiblebase 1, polyimide, polyethylene terephthalate, or the like is used, forexample.

The flexible wiring layer 2 is a conductive layer formed of a copperfoil, another metal foil, or the like. The flexible wiring layer 2 has awiring pattern. The flexible wiring layer 2 is formed on one side orboth sides of the flexible base 1. A conductor forming the flexiblewiring layer 2 is a substance having higher conductivity and higherthermal conductivity than the insulator, for example, a metal such ascopper, silver, gold, or the like. Note that the flexible wiring layer 2may be formed on at least one face of the flexible base 1.

The coverlay 3 is an insulating layer that protects a circuit formed ofthe flexible wiring layer 2. The coverlay 3 is formed of a coverlayfilm, an overcoat, or the like. The coverlay 3 is formed so as to coverthe flexible wiring layer 2 on the face on which the flexible wiringlayer 2 of the flexible base 1 is formed.

At the end part of the flexible wiring member 4, the coverlay 3 is notformed, and the flexible wiring layer 2 is exposed. The exposed part ofthe flexible wiring layer 2 forms a first electrode 5. A plurality offirst electrodes 5 are arranged at a predetermined pitch. In such a way,the first electrode 5 is formed of the flexible wiring layer 2 exposedat the end part of the flexible wiring member 4.

The printed wiring board 9 that is a wiring base has a printed wiringbase 6 that is a base, a wiring layer 7 that is a second wiring layer,and a second insulating layer 8.

Note that, in the present embodiment, while the case where the number ofwiring layers in the printed wiring board 9 is four is described, thenumber of wiring layers is not limited to four. The wiring layer in theprinted wiring board 9 may be a single layer or multiple layers, thatis, may have four or less layers or four or more layers.

The printed wiring base 6 that is a base is an insulating base made of arigid composite material or the like and shaped in a board, for example.Unlike the flexible base 1, the printed wiring base 6 is a rigidmaterial. An insulator forming the printed wiring base 6 may haveelectrical insulation. For example, as the printed wiring base 6, anorganic wiring circuit board using a glass epoxy base, a ceramic wiringcircuit board using ceramic, or a metal core wiring circuit board havinga metal core layer may be used. Further, a base is not limited to aprinted wiring base and may be a silicon substrate.

The wiring layer 7 is a conductive layer formed of a copper foil,another metal foil, or the like. The wiring layer 7 has a wiringpattern. The wiring layer 7 is formed on one face or both faces of theprinted wiring base 6. Further, one or multiple layers of the wiringlayers 7 are formed inside the printed wiring base 6. FIG. 1A representsthe case where four layers of the wiring layers 7 in total are formed onthe both faces and the inside of the printed wiring base 6. A conductorforming the wiring layer 7 is a substance having higher conductivity andhigher thermal conductivity than the insulator, for example, a metalsuch as copper, silver, gold, or the like. Note that the wiring layer 7may be formed on at least one face of the printed wiring base 6.

The second insulating layer 8 is an insulating protection film thatprotects a circuit formed of the wiring layer 7. In the firstembodiment, the second insulating layer 8 is formed of a cured liquidsolder resist, a film-like solder resist, or the like. Note that, as thesecond insulating layer 8, a nitride or an oxide such as SiN or Al₂O₃having high insulation may also be used. The second insulating layer 8is formed so as to cover the wiring layer 7 on the surface on which thewiring layer 7 of the printed wiring base 6 is formed.

An opening 12 is formed in the second insulating layer 8. The wiringlayer 7 is exposed in the opening 12. The exposed part of the wiringlayer 7 forms a second electrode 10. A plurality of second electrodes 10are arranged at a predetermined pitch. In such a way, the secondelectrode 10 is formed of the wiring layer 7 exposed in the opening 12.Note that, as long as electrical connection is possible, a protectionfilm formed of a metallic oxide or a metallic nitride may be provided ina part of the second electrode 10.

The flexible wiring member 4 is mounted on the face on which the secondelectrode 10 of the printed wiring board 9 is exposed in a state where aface on which the first electrode 5 is formed faces the printed wiringboard 9. A part in which the first electrode 5 of the flexible wiringmember 4 is exposed is referred to as the end part. The first electrode5 and the second electrode 10 are arranged to face each other so as toat least partially overlap in plan view from a direction perpendicularto the printed wiring board 9.

The end of the flexible wiring member 4 is arranged so as to be bentobliquely and fall in the opening 12 formed in the second insulatinglayer 8. The end of the flexible wiring member 4 falls in the opening 12with the first electrode 5 facing the second electrode 10 in the opening12. That is, the end part of the flexible wiring member 4 is fit in theopening 12 with the first electrode 5 facing the second electrode 10 inthe opening 12. Thereby, the end of the flexible wiring member 4 isarranged in the opening 12. In other words, the end of the flexiblewiring member 4 is arranged on the opening 12 in plan view.

Note that not whole the end of the flexible wiring member 4 is requiredto be arranged in the opening 12. The end of the flexible wiring member4 may be partially arranged in the opening 12 such that, for example,the part on the printed wiring board 9 side of the end falls and is fitin the opening 12.

The first electrode 5 exposed at the end part of the flexible wiringmember 4 that falls in the opening and the second electrode 10 exposedin the opening 12 are connected via solder 11 that is a conductiveconnection member. Since the end part of the flexible wiring member 4 isbent obliquely inside the opening 12, the first electrode 5 connected tothe second electrode 10 is inclined at a predetermined angle relative tothe second electrode 10.

The solder 11 that is a conductive connection member is solder that issolidified after heating of a solder-contained connecting material, andis a member that connects the first electrode 5 of the flexible wiringmember 4 to the second electrode 10 of the printed wiring board 9. Asolder-contained connecting material may be supplied by combiningSn-3.0% Ag-0.5% Cu solder or Sn-58% Bi solder with flux or may besupplied by containing solder particle powder in a thermosetting resinor a thermoplastic resin, for example. Further, as a solder-containedconnecting material, a solder pre-coat may be formed in advance on thefirst electrode 5 or the second electrode 10, and the flux may besupplied thereto. Note that the solder-contained connecting material isnot particularly limited and may be any conductive material that can fixand electrically connect the first electrode 5 and the second electrode10 to each other. Further, the conductive connection member is notlimited to solder, and a metal or a resin such as an anisotropicconductive film or an anisotropic conductive resin can be used.

Accordingly, the end part of the flexible wiring member 4 connected tothe printed wiring board 9 by the solder 11 is bent and falls in theopening 12 formed in the second insulating layer 8 of the printed wiringboard 9. On the other hand, the part opposite to the end of the flexiblewiring member 4 is laid on the second insulating layer 8 of the printedwiring board 9. Thereby, the flexible wiring member 4 has a part that isin contact with the second insulating layer 8. The end of the firstelectrode 5 side of the coverlay 3 is located inside the opening 12.

FIG. 1B is a top view illustrating the structure of the connectionportion between the flexible wiring member 4 and the printed wiringboard 9 in the electronic module 100 according to the presentembodiment. FIG. 1B illustrates the structure of the electronic module100 in plan view from a direction perpendicular to the printed wiringboard 9 viewed from the flexible wiring member 4 side.

As illustrated in FIG. 1B, the coverlay 3 is not formed at the end partof the flexible wiring member 4, and a plurality of first electrodes 5are formed of the exposed flexible wiring layer 2. The plurality offirst electrodes 5 are arranged at a predetermined pitch in the widthdirection along an edge side of the flexible wiring member 4, forexample.

Further, in the second insulating layer 8 of the printed wiring board 9,the opening 12 in which the wiring layer 7 is exposed is formed. Aplurality of second electrodes 10 are formed of the exposed wiring layer7 at the opening 12. For example, the plurality of second electrodes 10are arranged on the side of one long side of the rectangular opening 12so as to be arranged at a predetermined pitch in a direction along thelong side.

The first electrode 5 and the second electrode 10 are arranged to faceeach other for each of a plurality of pairs corresponding to each otherso as to at least partially overlap in plan view from the directionperpendicular to the printed wiring board 9.

Further, the width of the opening 12 is larger than the width of the endpart of the flexible wiring member 4 in a direction that isperpendicular to the direction of falling in the opening 12 at the endpart of the flexible wiring member 4 and parallel to the printed wiringboard 9. That is, the width of the opening 12 in the direction in whichthe plurality of second electrodes 10 are arranged is larger than thewidth of the end of the flexible wiring member 4 in the direction inwhich the plurality of first electrodes 5 are arranged. In such a way,the width of the end part of the flexible wiring member 4 is narrowerthan the width of the opening 12 in the width direction of the end part.Therefore, the end part of the flexible wiring member 4 is arranged soas to more easily fall in the opening 12. Thus, the first electrode 5and the second electrode 10 are more reliably connected via the solder11.

In such a way, according to the present embodiment, the first electrode5 and the second electrode 10 can be more reliably connected to via thesolder 11, even when these electrodes are arranged at a narrow pitchsuch that the electrode interval is 0.1 mm or less and the amount of thesolder-contained connecting material supplied onto the electrode issmall.

As described above, the electronic module 100 having the flexible wiringmember 4 and the printed wiring board 9 is configured. Note thatelectronic components may be mounted in any one or both of the printedwiring board 9 and the flexible wiring member 4. The electroniccomponent is not particularly limited, and various electronic componentsmay be mounted. In a sixth embodiment described below, a case where animaging sensor element 15 as an electronic component is mounted on aprinted wiring board 9 will be described.

A digital still camera or a digital video camera is required to transfera large amount of data between an imaging sensor and large scaleintegration (LSI) used for image processing due to the increased thenumber of pixels of a static image and a moving image or an increasedframerate. The imaging sensor is a complementary metal oxidesemiconductor (CMOS) image sensor, a charge coupled device (CCD) imagesensor, or the like. Further, to reduce the size of a product or toimprove the image stabilizing performance inside a camera in which imagestabilizing is performed by moving the imaging sensor, further reductionof the size of the imaging sensor module is required.

In general, a printed wiring board of an imaging sensor module mountedwith an imaging sensor and a printed wiring board mounted with LSI usedfor image processing are connected by a flexible wiring circuit boardvia a connecter. The connecter mechanically fixes the flexible wiringcircuit board by a metal spring or the like and causes the electrode ofthe flexible wiring circuit board and the electrode in the connecter tobe electrically contacted and conducted.

A greater amount of data transferred to the LSI used for imageprocessing from the imaging sensor requires a larger number of wiringsof the flexible wiring circuit board. On the other hand, since theconnecter mechanically fixes the flexible wiring circuit board, asmaller connecter has a smaller force for mechanically fixing theflexible wiring circuit board, which makes it difficult to haveconduction between the connecter and the electrode of the flexiblewiring circuit board. Thus, there is a limitation in reduction in sizeof the connecter. If such a connector were used for connection, as theamount of data transfer would increase and the number of wirings on theflexible wiring circuit board would increase, the size of the connectorwould be larger, and the size of the imaging sensor module would belarger.

Accordingly, Japanese Patent Application Laid-Open No. 2005-101026proposes the technique for direct connection between the electrodes bythermo-compression bonding using solder via no connecter. However, sincethe technique disclosed in Japanese Patent Application Laid-Open No.2005-101026 is required to secure the area corresponding to a rib partand a dam part used for suppressing the applied pressure and forming asolder pool, it is difficult to connect the electrodes to each other ina narrow area.

When the connection is made by using the solder 11 via no connecter, itis required that the first electrode 5 and the second electrode 10contact with the solder-contained connecting material, respectively, ina state where the solder-contained connecting material is heated at ahigher temperature than the melting point of the solder.

However, when the distance between the first electrodes 5 and thedistance between the second electrodes 10 are narrow, and the firstelectrode 5 and the second electrode 10 are arranged at a narrow pitch,respectively, the supplied amount of the solder-contained connectingmaterial supplied on the electrode decreases. As a result, the firstelectrode 5 and the second electrode 10 are less likely to be connectedto the solder 11, which is likely to cause a contact failure.

In contrast, in the present embodiment, the end part where the firstelectrode 5 of the flexible wiring member 4 is exposed falls in theopening 12 formed in the second insulating layer 8. Thereby, the endpart where the first electrode 5 of the flexible wiring member 4 isexposed is arranged in the opening 12. Such an arrangement of the endpart of the flexible wiring member 4 including the first electrode 5enables both of the first electrode 5 and the second electrode 10 to bereliably contacted by the solder 11. As a result, according to thepresent invention, the first electrode 5 of the flexible wiring member 4can be reliably connected to the second electrode 10 of the printedwiring board 9 via the solder 11. Moreover, according to the presentembodiment, since it is not required to secure the area corresponding tothe structure such as a rib part or a dam part, the first electrode 5and the second electrode 10 can be connected to each other at a narrowelectrode pitch.

On the other hand, when the solder-contained connecting materialcontacts to the adjacent electrode extruded out of between the firstelectrode 5 and the second electrode 10 when the first electrode 5 andthe second electrode 10 are connected to each other, the solder 11 andthe electrode may be short-circuited and cause a contact failure. Inparticular, when the first electrode 5 and the second electrode 10 arearranged at a narrow pitch, respectively, since the distance between theelectrodes is narrow, a short circuit failure between the electrodes mayoccur.

In contrast, in the present embodiment, the part opposite to the end ofthe flexible wiring member 4 is laid on the second insulating layer 8 ofthe printed wiring board 9. That is, the flexible wiring member 4 has apart contacting with the second insulating layer 8. Thus, on the sideopposite to the end of the flexible wiring member 4, at least a spacefrom the surface of the second electrode 10 of the printed wiring board9 to the surface of the second insulating layer 8 is secured. In thisspace, since the solder 11 can be held when the first electrode 5 andthe second electrode 10 are connected to each other, it is possible toprevent the solder 11 from extruding from a part between the firstelectrode 5 and the second electrode 10 and causing a short circuitfailure in the present embodiment.

Further, when the solder-contained connecting material extrudes over theopening 12 of the second insulating layer 8, the solder 11 interposedbetween by the flexible wiring member 4 on the second insulating layer 8moves, and a short circuit may occur between electrodes. Thus, it isdesirable that the volume V of the solder-contained connecting materialsupplied between the first electrode 5 and the second electrode 10 beless than or equal to a predetermined amount in terms of prevention of ashort circuit between the electrodes. That is, it is desirable that thevolume V of the solder-contained connecting material satisfy thefollowing Equation (1) where the area of the first electrode 5 isdenoted as S1, the area of the second electrode 10 is denoted as S2, andthe height from the surface of the second electrode 10 to the surface ofthe second insulating layer 8 is denoted as H1.

V<(S1+S2)/2×H1   Equation (1)

When the volume V of the solder-contained connecting material satisfiesthe above Equation (1), the solder does not extrude over the opening 12formed in the second insulating layer 8.

Further, it is desirable that the distance D1 between the firstelectrodes 5 and the distance D2 between the second electrodes 10 begreater than or equal to a predetermined distance in terms of preventionof a short circuit between electrodes, respectively. That is, it isdesirable that the distance D1 between the first electrodes 5 and thedistance D2 between the second electrodes 10 satisfy the followingEquations (2a) and (2b), respectively, where the height from the surfaceof the printed wiring base 6 to the surface of the second insulatinglayer 8 is denoted as H2, and the cross-sectional length in thetransverse direction of the opening 12 of the second insulating layer 8is denoted as L. The cross-sectional length L in the transversedirection of the opening 12 is a length of the opening 12 in thedirection along the surface of the printed wiring board 9 perpendicularto the direction in which the plurality of second electrodes 10 arearranged. Note that, in Equations (2a) and (2b), V is a volume of thesolder-contained connecting material supplied between the firstelectrode 5 and the second electrode 10 as described above.

D1≥V/(H2×L)   Equation (2a)

D2V/(H2×L)   Equation (2b)

In such a way, with the distances D1 and D2 between electrodes beingsecured, the volume of the space between electrodes is larger than thevolume V of the solder-contained connecting material arranged betweenthe first electrode 5 and the second electrode 10. Thus, a short circuitis less likely to occur between neighboring first electrodes 5 andbetween neighboring second electrodes 10.

In a general printed wiring board 9, the thickness of a copper foil usedas the second electrode 10 is around 5 to 20 μm, and the thickness ofthe second insulating layer 8 is 20 to 40 μm. In such a case, when eachwidth of the first electrode 5 and the second electrode 10 is 75 μm, itis desirable that the distance D1 between the first electrodes 5 and thedistance D2 between the second electrodes 10 be greater than or equal to66 μm, respectively. In the same case, when each width of the firstelectrode 5 and the second electrode 10 is 100 μm, it is desirable thatthe distance D1 between the first electrodes 5 and the distance D2between the second electrodes 10 be greater than or equal to 88 μm,respectively, and when each width of the first electrode 5 and thesecond electrode 10 is 200 μm, it is desirable that the distances D1 andD2 be greater than or equal to 175 μm, respectively.

Note that the area S1 of the first electrode 5 and the area S2 of thesecond electrode 10 may be the same or may not be the same.

Further, when the end of the flexible wiring member 4 is contacted withthe inner wall of the opening 12 formed in the second insulating layer8, the end part of the flexible wiring member 4 is less likely to fallin the opening 12. Accordingly, it is desirable that the end of theflexible wiring member 4 and the inner wall of the opening 12 bearranged so as to be spaced apart from each other by a certain distance.Specifically, taking the thermal expansion coefficient of the flexiblewiring member 4 and the connection temperature of the solder 11 intoconsideration, it is desirable that the end of the flexible wiringmember 4 and the inner wall of the opening 12 be spaced apart by adistance that is greater than or equal to the extension amount of theflexible wiring member 4 when the first electrode 5 and the secondelectrode 10 are connected to each other. It is desirable that such anarrangement relationship between the end of the flexible wiring member 4and the inner wall of the opening 12 be satisfied not only in thestructure obtained in heating for soldering by the solder 11 but also inthe structure obtained after the soldering. Note that, for example, thelinear expansion coefficient of the flexible wiring member 4 usingpolyimide as the flexible base 1 is less than or equal to 12 to 30ppm/degrees Celsius.

In such a way, according to the present embodiment, the flexible wiringmember 4 and the printed wiring board 9 can be directly connected toeach other at a narrow electrode pitch via no connecter.

FIRST EXAMPLE

An electronic module and a manufacturing method thereof according to thefirst example will be described. The flexible wiring member 4 wasconfigured to have polyimide of a thickness of 25 μm as the flexiblebase 1, a copper foil of a thickness of 6 μm as the flexible wiringlayer 2, and polyimide of a thickness of 15 μm as the coverlay 3. Thefirst electrode 5 was formed by exposing the copper foil of the flexiblewiring layer 2 in the cross-section direction by a width of 0.8 mm andin a direction perpendicular to the cross section by a width of 18 mm inFIG. 1A without providing the coverlay 3 at the end part of the flexiblewiring member 4. The first electrodes 5 had a width of 100 μm and werearranged at a pitch of 200 μm with a distance of 100 μm between theneighboring first electrodes 5.

The printed wiring board 9 was a four-layer substrate having a totalthickness of 500 μm, which was constructed by using FR-4 material as theprinted wiring base 6 and a copper foil as the wiring layer 7. In theprinted wiring board 9, the second insulating layer 8 having a thicknessof 20 μm was opened to form the opening 12 having an opening width of 20mm, an opening length of 1 mm, and an opening depth of 20 μm. Further,the copper foil having a thickness of 12 μm of a surface layer isexposed in the cross-section direction of FIG. 1A by a width of 1 mm toform the second electrode 10. As a solder-contained connecting materialin advance, a Sn-3.0% Ag-0.5% Cu solder pre-coat was formed on thesecond electrode 10, and flux was supplied on the second electrode 10.

The first electrode 5 and the second electrode 10 were arranged so as toface each other so that at least a part thereof overlapped in plan viewfrom a direction perpendicular to the printed wiring board 9. Further,the end part of the flexible wiring member 4 was arranged so as to fallin the opening 12 formed in the second insulating layer 8. In addition,the part opposite to the end of the flexible wiring member 4 was laid onthe second insulating layer 8 of the printed wiring board 9. At thistime, the end of the flexible wiring member 4 on the first electrode 5side of the coverlay 3 was arranged so as to be located inside theopening 12 formed in the second insulating layer 8 of the printed wiringboard 9.

The part on the end side of the flexible wiring member 4 were then fixedto the printed wiring board 9 by a polyimide tape. In this state, reflowheating was performed such that the peak temperature of thesolder-contained connecting material was larger than or equal to 220degrees Celsius and less than 250 degrees Celsius, and the firstelectrode 5 and the second electrode 10 were connected to each other bysoldering. The polyimide tape was then removed.

Note that the linear expansion coefficient of the flexible wiring member4 was around 15 ppm/degrees Celsius. Thus, taking an extension amount ofabout 30 μm at the end part of 0.8 mm of the flexible wiring member 4 at250 degrees Celsius into consideration, the end of the flexible wiringmember 4 was connected in a state where the end was arranged about 50 μmaway from the inner wall of the opening 12 of the second insulatinglayer 8. At this time, the end of the flexible wiring member 4 wasconnected to the surface of the second electrode 10 of the printedwiring base 6 with an inclination of about 2 degrees.

Connection using such a structure enabled the flexible wiring member 4and the printed wiring board 9 to be connected to each other at a narrowelectrode pitch of 200 μm.

Second Embodiment

The structure of an electronic module according to the second embodimentof the present invention will be described with reference to FIG. 2.FIG. 2 is a sectional view illustrating a structure of a connectionportion between a flexible wiring circuit board and a printed wiringboard in an electronic module according to the present embodiment.

The basic structure of the electronic module according to the presentembodiment is substantially the same as the structure of the electronicmodule according to the first embodiment. The electronic moduleaccording to the present embodiment is different from the firstembodiment in the position of the end of the coverlay 3 on the firstelectrode 5 side with respect to the opening 12 formed in the secondinsulating layer 8.

As illustrated in FIG. 2, the electronic module 100 according to thepresent embodiment has the flexible wiring member 4 and the printedwiring board 9 mounted by directly connecting to the flexible wiringmember 4 by soldering as with the first embodiment.

The end part of the flexible wiring member 4 is arranged so as to bebent and fall in the opening 12 formed in the second insulating layer 8as with the first embodiment. The first electrode 5 exposed at the endpart and the second electrode 10 exposed in the opening 12 are connectedvia the solder 11 as with the first embodiment.

Accordingly, the end part of the flexible wiring member 4 connected tothe printed wiring board 9 by the solder 11 is bent and falls in theopening 12 formed to the second insulating layer 8 as with the firstembodiment. The part opposite to the end of the flexible wiring member 4is also laid on the second insulating layer 8 of the printed wiringboard 9 as with the first embodiment.

On the other hand, in the present embodiment, unlike the firstembodiment, the edge of the coverlay 3 on the first electrode 5 side islocated outside the opening 12 formed in the second insulating layer 8.Thereby, the edge of the coverlay 3 on the first electrode 5 side islocated on the second insulating layer 8. In such a way, since thecoverlay 3 is arranged such that the edge of the first electrode 5 sideof the coverlay 3 is located on the second insulating layer 8, the areaof the end part of the flexible wiring member 4 that falls in theopening 12 can be larger than the area of the end part of the flexiblewiring member 4 that falls in the opening 12 in the present embodimentcompared to the first embodiment.

In such a way, according to the present embodiment, by increasing thearea of the end part of the flexible wiring member 4 that falls in theopening 12, it is possible to increase the connection area between thefirst electrode 5 and the second electrode 10. That is, according to thepresent embodiment, the first electrode 5 and the second electrode 10can be more reliably contacted and connected via the solder 11 even whenthese electrodes are arranged at a narrow pitch such that the electrodeinterval is 0.1 mm, for example, or less and the amount of thesolder-contained connecting material supplied onto the electrode issmall.

SECOND EXAMPLE

An electronic module and a manufacturing method thereof according to thesecond example will be described. The flexible wiring member 4 wasconfigured to have polyimide of a thickness of 25 μm as the flexiblebase 1, a copper foil of a thickness of 6 μm as the flexible wiringlayer 2, and polyimide of a thickness of 15 μm as the coverlay 3. Thefirst electrode 5 was formed by exposing the copper foil of the flexiblewiring layer 2 in the cross-section direction by a width of 1.4 mm andin a direction perpendicular to the cross section by 24.6 mm in FIG. 2without providing the coverlay 3 in the end part of the flexible wiringmember 4. The first electrodes 5 had a width of 75 μm and were alignedat a pitch of 150 μm with a distance of 75 μm between the neighboringfirst electrodes 5.

The printed wiring board 9 was a four-layer substrate having a totalthickness of 500 μm, which was constructed by using FR-4 material as theprinted wiring base 6 and a copper foil as the wiring layer 7. In theprinted wiring board 9, the second insulating layer 8 having a thicknessof 20 μm was opened to form the opening 12 having an opening width of25.6 mm, an opening length of 1 mm, and an opening depth of 20 μm.Further, the opening 12 is formed, and the copper foil having athickness of 12 μm of a surface layer was exposed in the cross-sectiondirection of FIG. 2 by a width of 1 mm to form the second electrode 10.As a solder-contained connecting material in advance, a Sn-3.0% Ag-0.5%Cu solder pre-coat was formed on the second electrode 10, and flux wassupplied on the second electrode 10.

The first electrode 5 and the second electrode 10 were arranged so as toface each other so that at least a part thereof overlapped in plan viewfrom a direction perpendicular to the printed wiring board 9. Further,the end part of the flexible wiring member 4 is arranged so as to fallin the opening 12 formed in the second insulating layer 8. Further, thepart opposite to the end of the flexible wiring member 4 was laid on thesecond insulating layer 8 of the printed wiring board 9. At this time,the end of the flexible wiring member 4 on the first electrode 5 side ofthe coverlay 3 was arranged so as to be located outside the opening 12formed in the second insulating layer 8 of the printed wiring board 9.

The part on the end side of the flexible wiring member 4 was thenpressed and fixed by force at 0.03 to 0.1 MPa to the print wiring board9 with a tool T using a magnetic body. In this state, induction heatingwas performed such that the peak temperature of the solder-containedconnecting material was larger than or equal to 220 degrees Celsius andless than 250 degrees Celsius, and the first electrode 5 and the secondelectrode 10 were connected to each other by soldering.

Note that the linear expansion coefficient of the flexible wiring member4 was around 15 ppm/degrees Celsius. Thus, taking an extension amount ofabout 30 μm at the end part of 0.8 mm of the flexible wiring member 4 at250 degrees Celsius into consideration, the end of the flexible wiringmember 4 was connected in a state where the end was arranged about 50 μmaway from the inner wall of the opening 12 formed in the secondinsulating layer 8. At this time, the end of the flexible wiring member4 was connected to the surface of the second electrode 10 of the printedwiring base 6 with an inclination of about 2 degrees.

Connection using such a structure enabled the flexible wiring member 4and the printed wiring board 9 to be connected to each other at a narrowelectrode pitch of 150 μm.

Manufacturing Method of Electronic Module

Next, a manufacturing method for manufacturing the electronic module 100according to the first embodiment will be described with reference toFIG. 3A to FIG. 3C. FIG. 3A, FIG. 3B, and FIG. 3C are sectional viewsillustrating a manufacturing method of the electronic module 100according to the first embodiment. Note that an electronic module 100according to the second embodiment can also be manufactured bysubstantially the same method. Note that the manufacturing method formanufacturing the electronic module 100 includes a connection method forconnecting the flexible wiring member 4 and the printed wiring board 9to each other.

First, as illustrated in FIG. 3A, in the printed wiring board 9, asolder-contained connecting material 11 a is supplied on the secondelectrode 10 exposed in the opening 12 formed in the second insulatinglayer 8. It is desirable that the volume V of the solder-containedconnecting material satisfy Equation (1) as described in the firstembodiment.

Next, as illustrated in FIG. 3B, the first electrode 5 of the flexiblewiring member 4 and the second electrode 10 on the printed wiring board9 are aligned so as to face each other, and the end part of the flexiblewiring member 4 is arranged so as to fall in the opening 12 formed inthe second insulating layer 8. At this time, for example, it isdesirable that the solder-contained connecting material 11 a haveviscosity like a solder paste, and the end part of the flexible wiringmember 4 be temporarily fixed to the printed wiring board 9. Further,for example, the end part of the flexible wiring member 4 may be fixedto the printed wiring board 9 by using a heat-resisting tape such as apolyimide tape or a heat-resisting adhesive agent. Thus, the firstelectrode 5 and the second electrode 10 are contacted with thesolder-contained connecting material 11 a.

Further, it is desirable that the end of the flexible wiring member 4and the inner wall of the opening 12 be arranged so as to be spacedapart from each other by a certain distance as described in the firstembodiment.

Next, the end part of the flexible wiring member 4 is caused to fall inthe opening 12 formed in the second insulating layer 8, and the firstelectrode 5 and the second electrode 10 are then heated in contact withthe solder-contained connecting material 11 a. Accordingly, solder ofthe solder-contained connecting material 11 a is melted. Aftercompletion of the heating, a junction part obtained by soldering iscooled by naturel cooling, cooling with a cooler, or the like.Accordingly, as illustrated in FIG. 3C, the first electrode 5 and thesecond electrode 10 are connected via the solder 11. By doing so, it ispossible to reliably connect the first electrode 5 and the secondelectrode 10 to each other and connect the first electrode 5 and thesecond electrode 10 to each other while preventing the solder 11 fromextruding from a part between the first electrode 5 and the secondelectrode 10 and causing a short circuit failure.

A method for melting solder is not particularly limited, and wholeheating such as reflow heating may be a method for melting solder, forexample. Further, for example, a method for melting solder may becontact local heating using a soldering copper or the like ornon-contact local heating such as a spot reflow or a laser using a hotblast or a lamp, or induction heating or dielectric heating. With theuse of non-contact local heating, even when an electronic componenthaving a low heat resistance is mounted on one or both of the printedwiring board 9 and the flexible wiring member 4, the printed wiringboard 9 can be connected to the flexible wiring member 4 withoutaffecting the electronic component.

Note that, while the case where the solder-contained connecting material11 a is supplied on the second electrode 10 has been described above,instead of or in addition to the above, the solder-contained connectingmaterial 11 a can also be supplied on the first electrode 5. Further, amanner to supply the solder-contained connection member 11 a is notparticularly limited and, for example, the solder-contained connectingmaterial 11 a can be supplied in a form of paste, or thesolder-contained connecting material 11 a can be supplied in a form ofpre-coat.

Next, another manufacturing method for manufacturing the electronicmodule 100 according to the first embodiment will be described withreference to FIG. 4A to FIG. 4C. FIG. 4A, FIG. 4B, and FIG. 4C aresectional views illustrating another manufacturing method of theelectronic module 100 according to the first embodiment. Note that anelectronic module 100 according to the second embodiment can also bemanufactured by substantially the same method. Note that themanufacturing method for manufacturing the electronic module 100includes a connection method for connecting the flexible wiring member 4and the printed wiring board 9 to each other.

First, as illustrated in FIG. 4A, in the printed wiring board 9, asolder-contained connecting material 11 a is supplied on the secondelectrode 10 exposed in the opening 12 formed in the second insulatinglayer 8. It is desirable that the volume V of the solder-containedconnecting material satisfy Equation (1) as described in the firstembodiment.

Next, as illustrated in FIG. 4B, the first electrode 5 of the flexiblewiring member 4 and the second electrode 10 on the printed wiring board9 are aligned so as to face each other, and the end part of the flexiblewiring member 4 is arranged so as to fall in the opening 12 formed inthe second insulating layer 8. Thus, the first electrode 5 and thesecond electrode 10 are contacted with the solder-contained connectingmaterial 11 a.

Further, it is desirable that the end of the flexible wiring member 4and the inner wall of the opening 12 be arranged so as to be spacedapart from each other by a certain distance as described in the firstembodiment.

Next, the end part of the flexible wiring member 4 was pressed with thetool T. Further, while being pressed by the tool T, the end part of theflexible wiring member 4 is caused to fall in the opening 12 formed in asolder resist, and the first electrode 5 and the second electrode 10 arethen heated in contact with the solder-contained connecting material 11a. Accordingly, solder of the solder-contained connecting material 11 ais melted. After completion of the heating, a junction part obtained bysoldering is cooled by naturel cooling, cooling with a cooler, or thelike. Accordingly, as illustrated in FIG. 4C, the first electrode 5 andthe second electrode 10 are connected via the solder 11. By doing so, itis possible to reliably connect the first electrode 5 and the secondelectrode 10 to each other and connect the first electrode 5 and thesecond electrode 10 to each other while preventing the solder 11 fromextruding from a part between the first electrode 5 and the secondelectrode 10 and causing a short circuit failure.

Note that, while the tool T that is a jig for pressing the end part ofthe flexible wiring member 4 is not particularly limited, a heating toolsuch as a soldering copper may be used, for example. Further, when theheating for melting solder is local heating by a hot air, the tool T maybe a nozzle that blows out hot air. Further, in a case of local heatingusing light of a lamp, a laser, or the like, a light guide plate thatguides light may be used as the tool T. By using such a tool T, whileenhancing the locality at the local heating, it is possible to connectthe flexible wiring member 4 and the printed wiring board 9 to eachother. Similarly, heating efficiency may be improved by using adielectric material for the tool T when heating for melting solder isdielectric heating, and by using magnetic material for the tool T whenheating for melting solder is induction heating.

Further, the end part of the tool T that presses the end part of theflexible wiring member 4 may have a slope so that the end side of theflexible wiring member 4 is lower than the side opposite to the end ofthe flexible wiring member 4. That is, the tool T may have an inclinedslope so that the distance between the second electrode 10 and theflexible wiring member 4 becomes smaller toward the end side of theflexible wiring member 4 and the end part of the flexible wiring member4 falls in the opening 12.

With the end part of the tool T having such a slope, when the tool Tpresses the end part of the flexible wiring member 4, the firstelectrode 5 and the second electrode 10 can be connected to each otherwhile being reliably contacted with the solder-contained connectingmaterial 11 a on the end side of the flexible wiring member 4. On theother hand, on the side opposite to the end of the flexible wiringmember 4, a space can be secured between the first electrode 5 and thesecond electrode 10, and it is possible to connect the first electrode 5and the second electrode 10 to each other while preventing the solder 11from extruding from a part between the first electrode 5 and the secondelectrode 10 and causing a short circuit failure.

Note that, while the case where the solder-contained connecting material11 a is supplied on the second electrode 10 has been described above,instead of or in addition to the above, the solder-contained connectingmaterial 11 a can also be supplied on the first electrode 5. Further, amanner to supply the solder-contained connection member 11 a is notparticularly limited and, for example, the solder-contained connectingmaterial 11 a can be supplied in a form of paste, or thesolder-contained connecting material 11 a can be supplied in a form ofpre-coat.

Electronic Component

Third Embodiment

An electronic component according to the third embodiment of the presentinvention will be described with reference to FIG. 5. FIG. 5 is asectional view illustrating an electronic component according to thepresent embodiment.

In the present embodiment, as an electronic component, an imaging unitusing the electronic module 100 having the flexible wiring member 4 andthe printed wiring board 9 will be described. The flexible wiring member4 and the printed wiring board 9 and the electronic module 100 havingthe flexible wiring member 4 and the printed wiring board 9 are the sameas described in the above first and second embodiments.

As illustrated in FIG. 5, an imaging unit 19 according to the presentembodiment has an imaging sensor module 14 and the flexible wiringmember 4. The imaging sensor module 14 has the printed wiring board 9,an imaging sensor element 15 that is an imaging element, a frame member17, and a cover glass 16.

The flexible wiring member 4 has the flexible base 1, the flexiblewiring layer 2, and the coverlay 3. At the end part of the flexiblewiring member 4, the coverlay 3 is not formed, and the flexible wiringlayer 2 is exposed. The exposed part of the flexible wiring layer 2forms the first electrode 5.

The printed wiring board 9 has the printed wiring base 6, the wiringlayer 7, and the second insulating layer 8. The wiring layer 7 isexposed in the opening 12 formed in the second insulating layer 8. Theexposed part of the wiring layer 7 forms the second electrode 10.

The flexible wiring member 4 is mounted on the face on which the secondelectrode 10 of the printed wiring board 9 is exposed in a state where aface on which the first electrode 5 is formed faces the printed wiringboard 9. The first electrode 5 and the second electrode 10 are arrangedto face each other so as to at least partially overlap in plan view froma direction perpendicular to the printed wiring board 9.

The end part of the flexible wiring member 4 is arranged so as to fallin the opening 12 formed in the second insulating layer 8. The firstelectrode 5 exposed in the end part and the second electrode 10 exposedin the opening 12 are connected via the solder 11.

Accordingly, the end part of the flexible wiring member 4 connected tothe printed wiring board 9 by the solder 11 is bent and falls in theopening 12 formed in the second insulating layer 8 of the printed wiringboard 9. On the other hand, the part opposite to the end of the flexiblewiring member 4 is laid on the solder resist of the printed wiring board9.

In the imaging sensor module 14, the imaging sensor element 15 ismounted on the opposite side to the face on which the flexible wiringmember 4 of the printed wiring board 9 is connected. The frame member 17is arranged and provided on the circumference of the face on which theimaging sensor element 15 of the printed wiring board 9 is mounted. Thecover glass 16 is formed on the frame member 17 so as to face theimaging sensor element 15 without contacting with the imaging sensorelement 15. The imaging sensor element 15 is arranged at the hollow partsurrounded by the frame member 17 and the cover glass 16. The imagingsensor element 15 is electrically connected to a pad 23 used for wiringof the printed wiring board 9 via a metal wire 18.

Note that, while the case where the frame member 17 is provided has beendescribed in the present embodiment, the arrangement position is notlimited to the circumference of the printed wiring board 9. Further, thearrangement position of the imaging sensor element 15 may be in a hollowof the printed wiring board having a counterboring such as a cavitysubstrate, for example.

According to the present embodiment, the flexible wiring member 4 andthe printed wiring board 9 can be connected each other in a smaller areathan the case where the flexible wiring member 4 and the printed wiringboard 9 are connected using a connector, and therefore reduction in sizeof the imaging sensor module 14 can be realized.

The imaging unit 19 including the imaging sensor module 14 can form animaging apparatus such as a digital still camera or a digital videocamera as an electronic equipment, for example. That is, the imagingapparatus as an electronic equipment can be configured to have a casingand the imaging unit 19 including the imaging sensor module 14accommodated in the casing.

Imaging Unit

Fourth Embodiment

An imaging unit according to the fourth embodiment of the presentembodiment will be described with reference to FIG. 6A to FIG. 8C. FIG.6A is a top view illustrating an imaging unit 400 according to thepresent embodiment. FIG. 6B is a sectional view taken along a line A-A′of FIG. 6A. FIG. 6C is a sectional view taken along a line B-B′ of FIG.6A.

The imaging unit 400 is formed of the imaging sensor module 14, an imagestabilizing unit 410, and the flexible wiring member 4. The imagingsensor module 14 has the imaging sensor element 15 mounted on theprinted wiring board 9 and is formed of the frame member 17 and thecover glass 16 as with the third embodiment. The imaging sensor element15 is electrically connected to a pad 23 used for wiring of the printedwiring board 9 via the metal wire 18 as with the third embodiment.

The printed wiring board 9 and the flexible wiring member 4 areconnected via the solder 11 and form the electronic module 100 as withthe third embodiment. Furthermore, in the present embodiment, aconnection portion between the flexible wiring member 4 and the printedwiring board 9 is reinforced by a resin 21, as described below. Further,providing the resin 21 enables the structure in which peeling betweenthe printed wiring board 9 and the flexible wiring member 4 is unlikelyto occur.

FIG. 7A, FIG. 7B, and FIG. 7C illustrate the structure of connectionportion between the flexible wiring member 4 and the printed wiringboard 9 in a sectional view taken along the line A-A′, a sectional viewtaken along the line B-B′, and a sectional view taken along a line C-C′of FIG. 6A, respectively.

The flexible wiring member 4 is formed of the flexible base 1 havingflexibility, the flexible wiring layer 2, and the coverlay 3. At the endpart of the flexible wiring member 4, the coverlay 3 is not formed, andthe flexible wiring layer 2 is exposed. The exposed part of the flexiblewiring layer 2 forms the first electrode 5.

The printed wiring board 9 is formed of the printed wiring base 6, thewiring layer 7, and the second insulating layer 8. The opening 12 isformed in the second insulating layer 8. The second electrode 10 isformed of the wiring layer 7 exposed in the opening 12.

As illustrated in FIG. 7A, the first electrode 5 and the secondelectrode 10 are connected to each other by the solder 11. The end partof the flexible wiring member 4 is arranged so as to be bent obliquelyand fall in the opening 12 formed in the second insulating layer 8. Thesecond electrode 10 of the printed wiring board 9 is connected to thepad 23 used for wiring by a via 13. A base of the printed wiring board 9is a glass epoxy material, and the material of the wiring layer 7 isformed of a metal.

As illustrated in FIG. 7B, a connection portion between the flexiblewiring member 4 and the printed wiring board 9 is reinforced by theresin 21 so as to cover the coverlay 3 at both edge parts in the pitchdirection of wirings, that is, in the pitch direction of the firstelectrode 5 and the second electrode 10.

As illustrated in FIG. 7C, at both edge parts reinforced by the resin21, the resin 21 and the solder 11 are formed via a space 20 so as to bespaced apart from each other.

In such a way, the end part of the flexible wiring member 4 has theresin 21 covering the edge parts in the width direction at the endparts. The resin 21 and the solder 11 are arranged between the flexiblebase 1 and the printed wiring board 9 so as to be spaced apart from eachother.

Since the space 20 is present between the resin 21 and the solder 11,the force applied to the solder 11 when tensile force occurs in theflexible wiring member 4 is reduced compared to the case where the space20 is absent between the resin 21 and the solder 11 because the flexiblebase 1 has flexibility. Therefore, connection reliability is improved.

On the other hand, when the resin 21 is in contact with the solder 11,and there is no space between the resin 21 and the solder 11, force topull the flexible wiring member 4 is directly applied to the solder 11.It is thus desirable that the material of the resin 21 have lowerYoung's modulus than the material of the solder 11.

Moreover, even when a space between the resin 21 and the solder 11 isnot provided, an intermediate member 22 may be provided between theresin 21 and the solder 11 as illustrated in FIG. 8A to FIG.8C. FIG. 8A,FIG. 8B, and FIG. 8C illustrate another structure of connection portionbetween the flexible wiring member 4 and the printed wiring board 9 in asectional view taken along the line A-A′, a sectional view taken alongthe line B-B′, and a sectional view taken along the line C-C′ of FIG.6A, respectively.

The intermediate member 22 is formed of a material having lower Young'smodulus than the resin 21 and the solder 11. For example, theintermediate member 22 may be an elastic member such as a resin havinglow Young's modulus or flux included in a solder paste used forconnecting the solder 11.

In such a way, the electronic module 100 may have the intermediatemember 22 having a lower Young's modulus than the resin 21 and thesolder 11. In such a case, the resin 21 and the intermediate member 22are arranged to contact with each other and the intermediate member 22and the solder 11 are arranged to contact with each other between theflexible base 1 and the printed wiring board 9.

With the intermediate member 22 being provided, the force applied to thesolder 11 when tensile force occurs in the flexible wiring member 4 isreduced to be smaller than in the case where the resin 21 and the solder11 are in contact with each other. Therefore, connection reliability isimproved.

While not particularly limited, the resin 21 is an epoxy resin, forexample. Note that, since the resin 21 is provided after connecting thesolder 11, flux may be re-melted by heating for curing the resin 21.When flux is re-melted, flux further attaches onto the flexible wiringmember 4 or the printed wiring board 9 on the resin 21 side and inhibitsadhesion between the resin 21 and flexible wiring member 4 or theprinted wiring board 9. Thus, it is desirable that the resin 21 be aresin that can be cured at a room temperature or an ultraviolet-curableresin.

Electronic Equipment

Fifth Embodiment

An electronic equipment according to a fifth embodiment of the presentinvention will be described with reference to FIG. 9. FIG. 9 is adiagram illustrating a general configuration of an imaging apparatus asan example of the electronic equipment according to the presentembodiment.

A digital camera (camera) 600 as an imaging apparatus that is an exampleof electronic equipments is a digital single-lens reflex camera, forexample, and has a camera main body 200 and a replaceable lens (lensbarrel) 300 that is removable from the camera main body 200. In FIG. 9,the replaceable lens 300 is mounted on the camera main body 200. A casewhere the replaceable lens 300 is mounted on the camera main body 200and thereby the imaging apparatus is formed will be described below.

The camera main body 200 has a casing 201 and has a mirror 222, ashutter 223, an imaging unit 400 that is an electronic module, and animage processing circuit 224, which are arranged inside the casing 201.Further, the camera main body 200 has a liquid crystal display 225 fixedto the casing 201 so as to be exposed out of the casing 201. The imagingunit 400 has an image stabilizing unit 410, the imaging sensor module 14having the printed wiring board 9, and an electronic module 226.

The replaceable lens 300 has a casing 301, which is a replaceable lenshousing, and an imaging optical system 311 that is arranged inside thecasing 301 and, when the casing 301 (the replaceable lens 300) ismounted on the casing 201, captures an optical image on the imagingsensor module 14. The imaging optical system 311 has a plurality oflenses.

The casing 301 has a lens-side mount 301 a in which an opening isformed, and the casing 201 has a camera-side mount 201 a in which anopening is formed. The lens-side mount 301 a and the camera-side mount201 a are fit to each other, and thereby the replaceable lens 300 (thecasing 301) is mounted on the camera main body 200 (the casing 201). Thearrow X direction illustrated in FIG. 9 is the optical axis direction ofthe imaging optical system 311.

A light propagating in the arrow X direction through the imaging opticalsystem 311 is guided into the casing 201 through the opening of thelens-side mount 301 a in the casing 301 and the opening of thecamera-side mount 201 a in the casing 201. The mirror 222, the shutter223, and the like are provided in the arrow X direction in front of theimaging unit 400 along the arrow X direction inside the casing 201.

The imaging sensor module 14 accommodated in the casing 201 has theimaging sensor element 15 mounted on the printed wiring board 9 and isformed of the frame member 17 and the cover glass 16. The flexiblewiring member 4 is connected to the printed wiring board 9. The imagingsensor element 15 is a solid state imaging element such as a CMOS imagesensor, a CCD image sensor, or the like that photoelectrically convertsa captured optical image.

Further, the cover glass 16 is formed in the frame member 17 so as toface the imaging sensor element 15 without contacting with the imagingsensor element 15. The imaging sensor element 15 is arranged in a hollowpart surrounded by the frame member 17 and the cover glass 16.

The image sensor element 15 is electrically connected to the printedwiring board 9 by the pad 23 used for wiring through the metal wire 18.

Display Apparatus

Sixth Embodiment

The electronic equipment according to a sixth embodiment of the presentinvention will be described with reference to FIG. 10A and FIG. 10B.FIG. 10A and FIG. 10B are diagrams illustrating a general configurationof a display apparatus as an example of the electronic equipmentaccording to the present embodiment.

A display apparatus 700 that is an example of electronic equipments is adisplay, for example, and may be used for a monitor portion of animaging apparatus. As illustrated in FIG. 10A, a silicon substrate 9Fthat is a wiring circuit board is provided, and a light emitting element39, a second insulating layer 8F, a color filter 37, a resin 36, and acover glass 33 are stacked in this order on the silicon substrate 9F. Apackage part 32 forms the outer circumference of the display apparatusand surrounds the light emitting element 39, the second insulating layer8F, the color filter 37, the resin 36, and the cover glass 33. Further,a dust-proof glass 31 is provided on the package part 32 via an adhesiveagent (not illustrated).

The light emitting element 39 is an organic light emitting element andhas an anode and a cathode that are a pair of electrodes and an organiccompound layer arranged between these electrodes. The organic compoundlayer is a stacked member formed of one or a plurality of layers havingat least a light emitting layer. When the organic compound layer is astacked member formed of a plurality of layers, this organic compoundlayer may have any of a hole injection layer, a hole transport layer, anelectron blocking layer, a hole block layer (a hole inhibition layer, ahole/exciton blocking layer), an electron transport layer, and anelectron injection layer, for example, other than a light emittinglayer.

The second insulating layer 8F is a protection layer used forsuppressing time degradation of the light emitting element 39 and may bea metal nitride or a metal oxide having a high insulation, such as SiNor Al₂O₃, for example.

For a color filter 37, filters that transmit three colors of red, green,and blue, for example, may be used.

The resin 36 is used for the purpose of sealing and provided so as tofill the space between the cover glass 33, the color filter 37, a sealmember 34, and the second insulating layer 8F.

FIG. 10B is an enlarged view of a portion surrounded by the dashed lineof FIG. 10A. The flexible wiring member 4 is formed of the flexible base1 having flexibility, the flexible wiring layer 2, and the coverlay 3.The coverlay 3 is not formed at the end part of the flexible wiringmember 4, and the flexible wiring layer 2 is exposed. The exposedportion of the flexible wiring layer 2 forms the first electrode 5.

The second insulating layer 8F is provided on the silicon substrate 9F,and the opening 12 is formed in the second insulating layer 8F. Thesecond electrode 10F that is a Cu pad is formed in the opening 12. Asillustrated in FIG. 10B, the first electrode 5 and the second electrode10F are connected by an anisotropic conductive film (ACF) 11F that is aconductive connection member. The end part of the flexible wiring member4 is arranged so as to obliquely bend and fall in the opening 12 formedin the second insulating layer 8F. With the flexible wiring member 4having such a shape, the contact area between the flexible wiring member4 and the silicon substrate 9F can be reduced as with the first to fifthembodiments.

Further, as illustrated in FIG. 10B, a resin 21F for reinforcement isprovided on the flexible base 1 is provided in the connection portionbetween the flexible wiring member 4 and the anisotropic conductive film(ACF) 11F. With the resin 21F being provided, the stress applied to theanisotropic conductive film 11F, which is a conductive connectionmember, is reduced when tensile force occurs in the flexible wiringmember 4, and connection reliability is improved.

Modified Embodiments

Various modifications can be made to the present invention without beinglimited to the embodiments described above. For example, while theimaging sensor module 14 has been described as a device having theprinted wiring board 9 in the above third embodiment as an example, theexample is not limited thereto. The device may be any type of devices,and other than the imaging sensor module 14, devices having variousprinted wiring boards 9 such as a printed wiring board 9 on which an LSIis mounted can be connected.

Further, the electronic module according to the embodiments describedabove may be accommodated in a casing to form various electronicequipments other than the imaging apparatus.

According to the present invention, a flexible wiring member and awiring circuit board can be directly connected by a small area.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2019-009363, filed Jan. 23, 2019, and Japanese Patent Application No.2019-227601, filed Dec. 17, 2019, which are hereby incorporated byreference herein in their entirety.

What is claimed is:
 1. An electronic module comprising: a flexiblewiring member comprising a flexible base, a first wiring layer formed onat least one face of the flexible base, and a first electrode formed ofthe first wiring layer at an end part that is not covered by a firstinsulating layer; a wiring circuit board comprising a base provided witha wiring, a second insulating layer having an opening formed on at leastone face of the base, and a second electrode formed in the opening; anda conductive connection member that connects the first electrode and thesecond electrode to each other, wherein an end of the flexible wiringmember is arranged above the opening in plan view.
 2. The electronicmodule according to claim 1, wherein the first electrode is connected tothe conductive connection member inside the opening.
 3. The electronicmodule according to claim 1, wherein the first electrode is arrangedwith an inclination relative to the second electrode.
 4. The electronicmodule according to claim 1, wherein the flexible wiring member has aportion contacting with the second insulating layer.
 5. The electronicmodule according to claim 1, wherein an edge on the first electrode sideof the first insulating layer is located on the second insulating layer.6. The electronic module according to claim 1, wherein a width of theend part is smaller than a width of the opening in a width direction ofthe end part.
 7. The electronic module according to claim 1, wherein theend part is arranged so as to be spaced apart from an inner wall of theopening.
 8. The electronic module according to claim 1, wherein theelectronic module further comprises a resin covering an edge part in awidth direction of the end part, and wherein the resin and theconductive connection member are arranged so as to be spaced apart fromeach other between the flexible base and the wiring circuit board. 9.The electronic module according to claim 1, wherein the conductiveconnection member is solder, wherein the end part further comprises aresin covering an edge part in a width direction of the end part,wherein the electronic module has an intermediate member having lowerYoung's modules than the resin and the solder, and wherein, between theflexible base and the wiring circuit board, the resin and theintermediate member are arranged to be contacted with each other, andthe intermediate member and the solder are arranged to be contacted witheach other.
 10. An electronic equipment comprising: a casing; and theelectronic module according to claim 1 accommodated in the casing. 11.An imaging sensor module comprising: the electronic module according toclaim 1; and an imaging element connected to the electronic module. 12.An imaging apparatus comprising: a casing; and the imaging sensor moduleaccording to claim 11 accommodated in the casing.
 13. A displayapparatus comprising: the electronic module according to claim 1; and alight emitting element connected to the electronic module